Cafeteria (category)
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| T. Fennel & DJ Patterson , 1988 |
Cafeteria is a genus of marine unicellular flagellates within the stramenopiles . They are small, bacteria-eating single-cell organisms.
features
The small, colorless cells are bean-shaped and around three to ten micrometers long. They do not have a cell envelope, i.e. neither a cell wall nor a pellicle . The two flagella start below the apex (subapical), often within a conspicuous pocket over which a lip-like structure hangs. The front-seated flagellum usually points directly forward, the rear one backwards. Sessile cells sitting on a solid surface rest on the tip of the posterior flagella. In this case, the anterior flagellum is used to generate a stream of water towards the cell body by means of helical movements. This behavior is characteristic of the bicosoecida group.
Ultrastructural
As with the other representatives of the stramenopiles, the anterior flagellum carries two rows of three-part mastigonemes . Cafeteria is characterized by three terminal fibrils , the middle one being longer than the lateral one. The cells have a nucleus. The only Golgi apparatus sits in front of the core near the base of the Scourge. There are around five sausage-shaped mitochondria . Typically for stramenopiles, the mitochondria have tubular cristae .
The cells have ejectile organelles called extrusomes. These are distributed in a characteristic pattern on the cell surface, especially near the cell mouth ( cytostome ). The cytoskeleton is based on an asymmetrical system, consisting of two flagella bases, three microtubule roots and a forked rhizoplast . One of the three microtubule roots attaches to the anterior basal body and is associated with secondary cytoskeletal microtubules. This is a common feature of stramenopiles. The other two microtubule roots attach to the posterior basal body. The distal ends of the two posterior roots do not overlap. The wider of the two roots has twelve microtubules and is divided distally into three subunits. These three subunits define the cell mouth (cytostome). This is shifted to the right in the cell axis.
Multiplication
Cafeteria multiplies through simple cell division. Sexual reproduction is not known, nor are permanent stages such as cysts.
nutrition
As far as is known so far, the species are obligately phagotrophic and feed on bacteria and small eukaryotes .
distribution
The five species are widespread in marine plankton and on many surfaces in the ocean. Typically for the bicosoecida, they adhere to the surfaces with their posterior flagella. Cafeteria roenbergensis is one of the most common and widespread species of heterotrophic nanoplankton. It occurs worldwide in sea water from near-surface water to the deep sea. The genus is not yet known in freshwater.
Systematics
The genus belongs to the small group Bicosoecida within the stramenopiles . There are several types, only some of which are described. The only better known is Cafeteria roenbergensis .
- Cafeteria roenbergensis
- Cafeteria minuta
- Marsupial cafeteria
- Cafeteria ligulifera
- Cafeteria mylnikovii
In addition, the following previously undescribed cultures are known:
- Cafeteria sp. CAFSW0510
- Cafeteria sp. EPM1
- Cafeteria sp. EWM2
- Cafeteria sp. GOT180
- Cafeteria sp. RCC1071
- Cafeteria sp. RCC970
swell
- Charles J. O'Kelly: Cafeteria. April 12, 2004, accessed March 1, 2013 .
Individual evidence
- ↑ Hartmut Arndt, Klaus Hausmann, Matthias Wolf: Deep-sea heterotrophic nanoflagellates of the Eastern Mediterranean Sea: qualitative and quantitative aspects of their pelagic and benthic occurrence . Mar Ecol Prog Ser, Volume 256, pp. 45–56, 2003. online (PDF; 634 kB)
- ↑ Genus: Cafeteria in the AlgaeBase
- ^ A b c Patterson in Encyclopedia of Life , accessed March 4, 2008.
- ↑ NCBI
